The child-resistant molded plastic container lid for open head containers of the present invention is of the type disclosed in U.S. Pat. No. 4,732,288, dated Mar. 22, 1988, wherein a threaded connection is provided between the container and lid, and the lid is provided with at least one resiliently biased locking member, and in certain embodiments with a pair of diametrically disposed resiliently biased locking members, pivotally connected to the closure lid, which cooperate with locking teeth on the container.
In the continuing research and development to improve the child-resistant molded plastic container lid and open head container disclosed in my above-mentioned patent, the lid and container of the present invention have been devised wherein the lever arms of the locking members are offset and substantially parallel to each other on opposite sides of the pivotal connection. An elliptical spring is integrally connected to each lever arm and cooperates with portions of a gusset wall enclosing the lever arms to provide continued biasing memory on the locking member.
A pair of openings or cut-outs are provided in the side wall of the lid rim for accommodating a respective lever arm of the locking member, and a thumb engaging portion of the lever arm.
An improved seal arrangement is also provided between the lid and the container to provide a tight and rigid seal and to reinforce the top of the container and lid to prevent the lid from popping off the container when it is dropped while full of liquid or powder.